What does it look like?
Deer are ruminant mammals. Males grow antlers in spring and shed them in winter. There are three species of deer present in Northland: red deer, sika deer and fallow deer. Red deer and fallow deer are farmed but sika deer is present only as a result of illegal releases. Red deer are the largest of the three species and tend to be reddish-brown, occasionally with white spots around the spine. Sika deer is one of the few deer species that does not lose its spots upon reaching maturity. Fallow deer are the most variable of any deer species in New Zealand with four quite distinctive colour phases. The most common colour is brown-black back with paler grey-brown underside and neck, and no spots.
Feral deer were not present in Northland prior to 1990. However, by 1997 increasing wild deer populations and related research findings prompted a range of agencies and farmer representatives to collaborate in a ten year multi-stakeholder campaign to remove all wild deer populations and halt their establishment and dispersal through reducing the risk of farm escapes and illegal liberations. Currently, deer are potentially living in the wild in at least eight separate locations in Northland (three sourced from illegal liberations and five from farm escapes), with numbers estimated to be just a few tens of animals. The programme has faced significant challenges, including many deer farm escapes and a clear desire by some landowners/hunters to illegally release deer.
Why is it a problem?
Deer are selective browsers and target particular forest species over others. This can result in significant changes to forest composition and has effects on the fauna that rely on those plants. Deer can destroy the understorey of native forest by browsing, grazing, bark stripping and trampling, which in turn may increase soil erosion. Feral deer can reduce production by damaging crops and exotic forests. They have also been implicated in the transmission of bovine Tb. To date there has been no positive identification of Tb in feral deer within the Northland Region.
The hinds are capable of producing a single calf (rarely twins) annually. Deer mate in autumn and the fawns are born in spring.